Structural iron form



(No Model.) 7 v T. s. WHITE. STRUCTURAL IRON FORM.

No. 496,466. Patented May 2, 1 893.

t 71 affainonms PETERS 00.. PHQTO-LIT UNITED STATES ATENT OFFICE.

TIMOTHY SIDNEY WHITE, OF NEW BRIGHTON, PENNSYLVANIA.

STRUCTURAL IRON FORM.

SPECIFICATION forming part of Letters Patent No. 496,466, dated May 2, 1893.

Application filed February 27, 1893l Serial No. 463,954- (No model.)

To all whom it may concern.-

Be it known thatI, TIMOTHY SIDNEY WHITE, a citizen of the United States, residing at New Brighton, in the county of Beaver, in the State of Pennsylvania, have invented certain new and useful Improvements in Structural Iron Forms; and I do hereby declare that the following is a full, clear, and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

This invention relates to a small yet important improvement upon forms set forth in pending applications, Serial Nos. 463,047, 463,048 and 433,651, filed, respectively, February 20, 1893, and May 20, 1892, the latter passed to issue October 7, 1892, the object being to secure a more symmetrical and more perfectly balanced section than appears in said applications.

In the accompanying drawings which form part of this specification,Figure 1 is'a cross sectional view of a novel structural unit. Fig. 2 isa like section of a member formed by adding to the unit of Fig. 1 two other units. Fig. 3 is a perspective view of a portion of the member of Fig. 2.

The applications above referredto show units and members analogous to the units and member herein described, the principal unit consisting of a main web having flanges united to its margins, respectively, by secondary Webs integral with both main web and flange and extending toward opposite sides of the main web. The member is made up by adding to this unit two Z-bars, each in position symmetrical with a secondary web and flange of the main unit and each having its central web and free flange equal to such secondary web and flange. The three units are each and all of substantially the same thickness throughout, and consequently the uniting flange of the Z-bar, throughout its extent, doubles the thickness of the member and thus renders the member unsymmetrical and imperfectly balanced. This fault it is the object of the present invention to avoid, it being in some cases a serious disadvantage.

In the drawings above designated, A is a main web, B, B are secondary webs extending out upon opposite sides of the plane of the main web, and O, O are flanges extending out upon opposite sides of the secondary webs, respectively. All these parts are integrally connected being rolled from a single piece of metal. The several angles made by the parts are in this instance shown as right angles but this is not essential. Z-bars E, E are added to this unit by rigidly uniting one flange of each to the main web A. They are so proportioncd that their central webs F and free flanges are equal, respectively, to the secondary webs and flanges of the main web and are so placed that-such equal parts are symmetrical with reference to the plane of the main web. Now as the uniting flanges of the Z-bars are added upon the faces, respectively of the main web, the latter would be unsymmetrical and we should not have a balanced section if the primary unit were of uniform thickness. It is not, therefore, so made but is made so much thicker at I), D, that the parts are symmetrical; that is, the thickness is increased in such manner and to such degree that the added metal is just equal to the metal in the uniting flange and is like placed with reference to the central plane of the main web. It is then evident that the whole section is perfectly balanced. Moreover, the extra metal is at a distance from the neutral axis and adds more to the strength of the member than it does to the weight, but it adds nothing to the difficulty of rolling and very little to the cost of the complete member.

The Z-bars are shown as riveted to the principal unit,but any method of rigidly join ing may be employed. 7

Having now fully set forth my invention, what I claim is-- 1. The structural iron unit having secondary webs integrally joined to, and extending toward opposite sides of, a main web whose marginal portions are thicker than its central portion, substantially as set forth.

2. The combination with a structural iron unit having secondary webs integrally connected, respectively, to the margins of amain web and extending toward opposite sides thereof of units each having a flange rigidly secured to the marginal portion of the main Web upon the side opposite the correspondrigidly joined to the main web and so pro- 10 ing secondary web, such main web being thickportioned and placed that the parts upon each ened upon the side opposite said flange to side of the centralplane of the main web shall balance the same. be equal and symmetrical with reference to 5 3. The combination with the marginally that plane. it

thickened main Web having flanges integrally TIMOTHY SIDNEY WHITE. connected to its margins, respectively, bysec- \Vitnesses: ondary Webs extending out upon opposite FRITZ DEGNER, sides of the main Web, of two Z-bars each G. D. DoUGLAss. 

